Transporting device, image reading apparatus, and image forming apparatus

ABSTRACT

Provided is a transporting device including a first contact member having a first contact portion that contacts a medium transported, a second contact member having a second contact portion that contacts the medium transported, on the downstream side of the first contact portion in a transporting direction, the first contact portion and the second contact portion each having a tangential plane, and the tangential planes coinciding with each other, a transporting unit that transports the medium so that a first surface of the medium coincides with the tangential plane in a section of the first contact portion to the second contact portion, and a processing unit that is arranged between the first contact portion and the second contact portion, and performs processing on the first surface of the medium that is passing through a processing region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2013-170711 filed Aug. 20, 2013.

BACKGROUND Technical Field

The present invention relates to a transporting device, an image reading apparatus, and an image forming apparatus.

SUMMARY

According to an aspect of the invention, there is provided a transporting device including: a first contact member having a first contact portion that contacts a medium transported; a second contact member having a second contact portion that contacts the medium transported, on the downstream side of the first contact portion in a transporting direction, the first contact portion and the second contact portion each having a tangential plane, and the tangential planes coinciding with each other; a transporting unit that transports the medium so that a first surface of the medium coincides with the tangential plane in a section of the first contact portion to the second contact portion; and a processing unit that is arranged between the first contact portion and the second contact portion, and performs processing on the first surface of the medium that is passing through a processing region.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein:

FIGS. 1A and 1B are views showing an example of a hardware configuration of a transporting device of a first exemplary embodiment;

FIG. 2 is a view showing an example of a processed portion;

FIGS. 3A and 3B are enlarged views showing respective contact members;

FIGS. 4A to 4C are views showing an example of a state where a medium is transported along a transporting path;

FIG. 5 is a view showing an example of a state where a thick medium is transported along the transporting path;

FIG. 6 is a view showing an example of a hardware configuration of a transporting device in a second exemplary embodiment;

FIGS. 7A to 7C are views showing an example of a state where a medium is transported along a transporting path;

FIG. 8 is a view showing an example of a hardware configuration of a transporting device of a modification example;

FIG. 9 is a view showing an example of contact members of a modification example;

FIGS. 10A and 10B are views showing an example of a hardware configuration of a transporting device of a modification example;

FIG. 11 is a view showing another example of a hardware configuration of a transporting device of a modification example;

FIGS. 12A to 12D are views showing examples of contact regions of a modification example; and

FIGS. 13A and 13B are views showing an example of contact members of a modification example.

DETAILED DESCRIPTION [1] First Exemplary Embodiment

[1-1] Hardware Configuration

FIGS. 1A and 1B are views showing an example of a hardware configuration of a transporting device of a first exemplary embodiment. A transporting device 1 including a transporting path 2, a reader 3, a transporting unit 4, a first contact member 11, and a second contact member 12 is shown in this example. The transporting unit 4 is a unit having a contacting unit 20, a first transporting member 30, and a second transporting member 40. Only the transporting device 1 is shown in FIG. 1A, and a state where the transporting device 1 is transporting a medium P1, on which an image is formed by an image forming unit that is not shown, is shown in FIG. 1B. In the following, respective sections will be described referring to both of FIGS. 1A and 1B. The transporting path 2 is a path along which the medium P1 is transported. The medium P1 is transported in a transporting direction A1. In the present exemplary embodiment, the transporting direction A1 runs along a horizontal direction A2.

The reader 3 is an example of a processing unit that performs, when a medium transported in the transporting direction A1 along the transporting path 2 passes through a certain region (hereinafter referred as a “processing region”), processing on the portion of one surface (hereinafter referred to as a “first surface”) of the medium that is passing through the processing region. In FIG. 1B, the surface out of the surfaces of the medium P1 that is directed to an upper surface (hereinafter referred to as “upward”) in a vertical direction A3 is shown as a first surface Q1, and the surface that is directed to a lower surface (hereinafter referred to as “downward”) that is an opposite side of the upper surface is shown as a second surface Q2. The reader 3, specifically, performs the processing of irradiating the first surface Q1 with light and optically reading the image formed on the medium P1 on the basis of the reflected light of the light. In FIG. 1A, a processing region E1 of the reader 3 is shown by a dashed line. The processing region E1 represents a region where the reader 3 may read the image. F1, which is the portion of the first surface Q1 of the medium P1 that passes through the processing region E1 (hereinafter referred to as a “processed portion”), is shown in FIG. 1B. The processed portion F1 will be described with reference to FIG. 2.

FIG. 2 is a view showing an example of the processed portion F1. The processed portion F1 is shown by hatching in FIG. 2. The processed portion F1 has a rectangular shape including both end portions of the medium P1 in a width direction A4. The processed portion F1 moves in a direction opposite to the transporting direction A1 on the first surface Q1 as the medium P1 is transported. As a result, a whole image formed on the first surface Q1 is read by the reader 3. The image read by the reader 3 is compared with, for example, an image shown by image data used for formation of the read image, and is used in order to determine whether or not an accurate image is formed.

The description refers back to FIGS. 1A and 1B. The first contact member 11 is an example of a member having a first contact portion C11 that contacts the medium P1 transported, on the upstream side of the processing region E1 in the transporting direction A1. The second contact member 12 is an example of a member including a second contact portion C12 that contacts the medium P1 transported, on the downstream side of the processing region E1 in the transporting direction A1. The contacting unit 20 has a third contact member 21 and a fourth contact member 22. The third contact member 21 is an example of a member including a third contact portion C21 that contacts the medium P1 transported, on the upstream side of the first contact portion C11 in the transporting direction A1. The fourth contact member 22 is an example of a member including a fourth contact portion C22 that contacts the medium P1 transported, on the downstream side of the second contact portion C12 in the transporting direction A1.

All of these contact members are formed from materials such as iron, and are members that have sufficient strength such that the contact members are not deformed even if a medium contacts with them. For this reason, the respective contact portions do not change in position even if a medium contacts with them. Additionally, all of the contact members are planar on the surfaces thereof on the upstream side in the transporting direction A1, and are formed so that angles (θ12 shown in the drawing in the case of the second contact member 12) that the surfaces form with respect to the transporting direction A1 are smaller than the predetermined angles. These surfaces are portions that guide an end portion (that is, a leading edge) on a head side of a medium transported in the transporting direction A1 during the collision with the end portion, and the leading edge of the medium is not easily bent by making the aforementioned angles (for example, θ12) smaller than the predetermined angles.

The first transporting member 30 is an example of a member that transports a medium, and is provided on the upstream side of the third contact member 21 in the transporting direction A1. The first transporting member 30 has a first rotating member 31 and a second rotating member 32 that rotate in circumferential directions A5 and A6, respectively, around respective axes (B31 and B32) along the width direction A4. The first rotating member 31 and the second rotating member 32 form a nip region N1. The first transporting member 30 rotates the rotating members to transport a medium that contacts the surfaces of both of the rotating members in the nip region N1.

The second transporting member 40 is an example of a member that transports a medium, and is provided on the downstream side of the fourth contact member 22 in the transporting direction A1. The second transporting member 40 has a first rotating member 41 and a second rotating member that rotate in circumferential directions A7 and A8, respectively, around respective axes (B41 and B42) along the width direction A4. The first rotating member 41 and the second rotating member 42 form a nip region N2. The second transporting member 40 rotates the rotating members to transport a medium that contacts the surfaces of both of the rotating members in the nip region N2.

Additionally, the first rotating member 41 and the second rotating member 42 of the second transporting member 40 rotate so that a speed (hereinafter referred to as a “surface speed”) V2 at which the respective surfaces of the rotating members move in the circumferential directions A7 and A8, respectively, is faster than a surface speed (a speed at which the surfaces of the first rotating member 31 and the second rotating member move in the circumferential directions A5 and A6, respectively) V1 in the first transporting member 30 (that is, V2>V1). As a result, forces by which the medium P1 is pulled toward the front and rear nip regions N1 and N2 (that is, in directions of arrows M1 and M2 in FIG. 1B) along the transporting direction A1 are applied to the medium P1.

FIGS. 3A and 3B are enlarged views showing the respective contact members of FIGS. 1A and 1B. The forms of the first contact portion C11 and the second contact portion C12 will be described with reference to FIG. 2. The contact regions D11 and D12 of the first surface Q1 of the medium P1, which are regions that contact the first contact portion C11 and the second contact portion C12, are shown by hatching in FIG. 2. Both of the contact regions D11 and D12 extend straight without being cut from one end portion of the first surface Q1 to the other end portion thereof along the width direction A4. As shown by the contact regions, both of the first contact portion C11 and the second contact portion C12 extend straight along the width direction A4. A tangential plane G10 tangent to both of the first contact portion C11 and the second contact portion C12 that have such forms is shown in FIG. 3A.

The tangential plane will be described with reference to FIG. 3B. FIG. 3B enlarges and shows the vicinity of the second contact portion C12 of the second contact member 12 as viewed in the width direction A4 described in FIG. 2. The vicinity of the second contact portion C12 has a roundish form as shown in the drawing. Since this form continues in the width direction A4, the surface of the vicinity of the second contact portion C12 is a curved surface. Tangential planes G10, G11, G12, and G13 tangent to the curved surface in respective spots on the curved surface are shown in FIG. 3B. The tangential plane G10 is a tangential plane tangent to a lowermost point R12 among the tangential planes, and is a tangential plane along the transporting direction A1. The point R12 is a point included in the second contact portion C12. In addition, the tangential plane G10 is also a tangential plane in another point in the width direction A4 of the point R12. The first contact portion C11 also has a roundish form similarly to the second contact portion C12, and a tangential plane that is tangent the lowermost point and runs along the transporting direction A1 becomes G10. In this way, the second contact portion C12 has the tangential plane G10 common to the first contact portion C11.

Similarly to the first contact portion C11 and the second contact portion C12, the third contact portion C21 and the fourth contact portion C22 also have a form of extending straight along the width direction A4, and have a tangential plane (G20 shown in FIG. 3A) common to each other. Both of the tangential planes G10 and G20 are planes along the transporting direction A1 and the width direction A4. The tangential plane G10 has a distance L1 from the reader 3, and has a distance L2 from the tangential plane G20. Additionally, a plane including the nip regions N1 and N2 shown in FIG. 1A, that is, a common tangential plane G30 on the first rotating member 31, the second rotating member 32, the first rotating member 41, and the second rotating member 42 is shown in FIG. 3A. In the present exemplary embodiment, the tangential plane G30 is sandwiched between the tangential planes G10 and G20, and both of the distances from both tangential planes become L3. That is, L3 becomes the length of half of L2 and the positions of the nip regions N1 and N2 in the vertical direction A3 become the middles of the tangential planes G10 and G20.

In the transporting device 1, when a medium having a thickness equal to or more than the distance L2 is transported, the first surface passes through the tangential plane G10 in a section (H1 shown in FIG. 3A) of the first contact portion C11 to the second contact portion C12. Here, the expression “the first surface passes through the tangential plane G10” means that a two-dimensional region referred to as the first surface moves while passing through a two-dimensional region referred to as the tangential plane G10. The mechanism thereof will be described with reference to FIGS. 4A to 4C and 5.

FIGS. 4A to 4C are views showing an example of a state where a medium is transported along the transporting path 2. A state where a medium P10 having a thickness of L2 is transported in the transporting direction A1 is shown in FIG. 4A. Forces by which the medium P10 is pulled in the directions of the arrows M1 and M2 are applied to the medium P10 as mentioned above. For this reason, the medium P10 is brought into a straight extending (that is, there is no deflection) state.

Here, the thickness of the medium P10 is L2 and falls in a gap between the tangential planes G10 and G20, and a plane containing the nip regions N1 and N2 is positioned at the middles of the tangential planes G10 and G20. Therefore, although the first surface Q11 of the medium P10 contacts the first contact portion C11 and the second contact portion C12, and the second surface Q12 contacts the third contact portion C21 and the fourth contact portion C22, the medium P10 is brought into a straight extending state. In this state, the first surface Q11 overlaps the tangential plane G10 and the second surface Q12 overlaps the tangential plane G20. That is, in a state shown in FIG. 4A, the first surface Q11 passes through the tangential plane G10 in a section H1.

A state where the upstream side of the medium P10 in the transporting direction A1 has moved up (the upper side in the vertical direction A3) is shown in FIG. 4B. In this case, the medium P10 is bent with the first contact portion C11 as a fulcrum. That is, the first contact portion C11 serving as the fulcrum and the first surface Q11 continue contacting each other. Additionally, even if a force (elastic force) that tries to return the medium P10 to a straight state tends to act on the medium P10 and the portion of the medium P10 located further in the downstream side in the transporting direction A1 than the first contact portion C11 tends to move downward, the downward movement is suppressed upward by the fourth contact portion C22. Therefore, such movement does not occur and the straight state is maintained in the transporting direction A1. Therefore, the first surface Q11 also continues contacting the second contact portion C12, and a state where the first surface Q11 overlaps the tangential plane G10 shown in FIGS. 3A and 3B is maintained in the section H1.

A state where the upstream side of the medium P10 in the transporting direction A1 has moved downward (lower side in the vertical direction A3) is shown in FIG. 4C. In this case, although the medium P10 tends to be bent with the third contact portion C21 as a fulcrum and an elastic force tends to act and the portion of the medium P10 located further toward the downstream side in the transporting direction A1 than the third contact portion C21 tends to move upward, such an upward movement is suppressed downward by the first contact portion C11. Therefore, such movement does not occur and a straight state is maintained in the transporting direction A1. Accordingly, the first surface Q11 continues contacting both of the first contact portion C11 and the second contact portion C12, and a state where the first surface Q11 overlaps the tangential plane G10 is maintained in the section H1.

FIG. 5 is a view showing an example of a state where a medium having a greater thickness than L2 is transported along the transporting path 2. A state where a medium P20 having a thickness of L4 (L4>L2) is transported is shown in FIG. 5. Since the medium P20 has a greater thickness than L2, the medium P20 is not brought into a straight extending state in the transporting direction A1 unlike the medium P10 shown in FIG. 4A, but is transported in a state where the medium P20 is pushed up and down and bent as shown in the drawing by the respective contact portions. In this case, the medium P20 receives an upward force from the third contact portion C21 and the fourth contact portion C22 and is brought into a state where the first surface Q21 is pressed against the first contact portion C11 and the second contact portion C12.

For this reason, the first surface Q21 continues contacting both of the first contact portion C11 and the second contact portion C12, and a state where the first surface Q21 overlaps the tangential plane G10 is maintained in the section H1. Additionally, even when the upstream side of the medium P20 in the transporting direction A1 moves upward or downward, the upward or downward movement is suppressed by the fourth contact portion C22 or the first contact portion CU similarly to the medium P10 shown in FIGS. 4B and 4C and thereby, a state where the first surface Q21 overlaps the tangential plane G10 is maintained in the section H1.

As described above, the transporting unit 4, that is, the third contact member 21, the fourth contact member 22, the first transporting member 30, and the second transporting member 40 transport a medium so that the first surface passes through the tangential plane G10 in the section H1 sandwiched between the respective contact portions (C11 and C12) of the first contact member 11 and the second contact member 12.

Additionally, the contacting unit 20 contacts the second surface of the medium at two positions. In the following, these two positions are referred to as a “first position” and a “second position”, respectively. In the example shown in FIG. 3A or the like, the first position is the position of the third contact portion C21, and is further apart by a first length from the processing unit (reader 3) than the tangential plane G10 on the upstream side of the first contact portion C11 in the transporting direction A1. Additionally, the second position is the position of the fourth contact portion C22, and is further apart by a second length from the processing unit (reader 3) than the tangential plane G10 on the downstream side of the second contact portion C12 in the transporting direction A1. The first and second lengths may be equal to and different from each other. In the present exemplary embodiment, both of the first length and second length become the thickness L2 of the medium P10. That is, in the present exemplary embodiment, the contacting unit 20 includes the third contact member 21 having the third contact portion C21 that contacts a medium transported, at the first position, and the fourth contact member 22 having the fourth contact portion C22 that contacts the medium at the second position. In addition, it is desirable that both of the first and second lengths be equal to or less than the thickness of a thinnest medium among media transported by the transporting device 1.

[1-2] Effects according to First Exemplary Embodiment

In the present exemplary embodiment, the transporting unit 4 transports a medium as described above. As a result, compared to a case that does not include a configuration in which a medium is transported so that the first surface passes through the tangential plane G10, the distance between the first surface of the medium and the reader 3, that is, the distance between the first surface and the reader 3 in the section H1, is easily maintained at L1. This is also true when the thicknesses of media are different as described in FIG. 5. That is, according to the present exemplary embodiment, compared to the case that does not include the above configuration, the position of the surface of media with respect to the processing unit (the reader 3 in the present exemplary embodiment) that performs processing on the surface of the media does not change easily even if the thicknesses of the media are different.

Additionally, in the present exemplary embodiment, the first transporting member 30 and the second transporting member 40 transport a medium, respectively, so that the respective surface speeds thereof become V1<V2. As a result, the forces by which a medium is pulled toward the front and rear nip regions N1 and N2 along the transporting direction A1 is applied to the medium as described above, and the medium does not easily sag in the transporting direction compared to a case where the respective rotating members do not rotate at the speeds V1 and V2.

Additionally, in the present exemplary embodiment, the contacting unit 20 contacts the second surface of a medium at the first and second positions. As a result, compared to a case where a medium is pressed down as described in the example of FIGS. 4A to 4C and 5 and the contacting unit does not contact the second surface at the first and second positions, the first surface easily continues contacting the first contact portion C11 and the second contact portion C12 and the first surface easily passes through the tangential plane G10.

Additionally, in the present exemplary embodiment, the third contact portion C21 of the third contact member 21 contacts a medium at the first position, and the fourth contact portion C22 of the fourth contact member 22 contacts the medium at the second position. That is, a specific spot of each contact member contacts a medium. On the other hand, for example, if a contact member is deformed by a force received from a medium and the spot of the contact member that contacts the medium changes, the first and second positions will move. In the present exemplary embodiment, the first and second positions are stabilized compared to a case that does not include the configuration in which the specific spot of the contact member contacts the medium in this way.

[2] Second Exemplary Embodiment

A second exemplary embodiment of the invention will be described below, mainly regarding the differences from the first exemplary embodiment. In the second exemplary embodiment, a case where a medium is transported so that the first surface passes through the tangential plane G10, without providing the third contact member 21 and the fourth contact member 22 that are described in the first exemplary embodiment, will be described.

[2-1] Hardware Configuration

FIG. 6 is a view showing an example of a hardware configuration of a transporting device in the second exemplary embodiment. In this example, a transporting device 1 a that is different from the transporting device 1 shown in FIGS. 1A and 1B in terms of the configuration of the transporting unit is shown. The transporting device 1 a includes a transporting path 2 a and a transporting unit 4 a. The transporting path 2 a is not provided with the third contact member 21 and the fourth contact member 22 that are shown in FIGS. 1A and 1B. That is, the transporting unit 4 a includes a contacting unit 20 a that does not have the two contact members. The contacting unit 20 a, similarly to the contacting unit 20, is a unit that contacts the second surface of a medium at the first and second positions. The contacting unit 20 a includes a first transporting member 30 a and a second transporting member 40 a.

The first transporting member 30 a and the second transporting member 40 a include a configuration common to the first transporting member 30 and the second transporting member 40 that are shown in FIGS. 1A and 1B except for the positions thereof in the vertical direction A3, and form nip regions N1a and N2a, respectively. The transporting members are arranged so that the positions (hereinafter referred to as “vertical-direction positions”) thereof in the vertical direction A3 are closer to the reader 3 than the respective transporting members shown in FIGS. 1A and 1B. Specifically, the first transporting member 30 a and the second transporting member 40 a are arranged so that a tangential plane G30a including the respective nip regions N1a and N2a is located at a position apart upward from the tangential plane G10 by a distance L5.

FIGS. 7A to 7C are views showing an example of a state where a medium is transported along the transporting path 2 a. In FIG. 7A, a medium P10 (a medium having a thickness of L2) shown in FIGS. 4A to 4C is transported along the transporting path 2 a. Since both of the nip regions N1a and N2a are above the first contact portion C11 and the second contact portion C12, the medium P10 is transported such that the first surface Q11 is pressed against the contact portions. Therefore, the medium is transported so that the first surface Q11 continues contacting the first contact portion C11 and the second contact portion C12 and passes through the tangential plane G10 in the section H1. Additionally, in the present exemplary embodiment, the first transporting member 30 a contacts the second surface Q12 at a first position, and the second transporting member 40 a contacts the second surface Q12 at a second position. The first and second positions in this example will be described with reference to FIG. 7B.

FIG. 7B enlarges and shows the periphery of the nip region N1a. The portions of the first rotating member 31 and the second rotating member 32 that contact the medium P10 are flatly deformed. Hereinafter, these portions are referred to as “deformed portions.” A deformed portion R31 of the first rotating member 31 contacts the second surface Q12 of the medium P10. In the present exemplary embodiment, a position where the deformed portion R31 and the second surface Q12 contact each other becomes the above-described first position. FIG. 7C enlarges and shows the periphery of the nip region N2a. In this example, a deformed portion R41 of the first rotating member 41 contacts the second surface Q12 of the medium P10. In the present exemplary embodiment, a position where the deformed portion R41 and the second surface Q12 contact each other becomes the above-described second position. FIG. 7A shows the tangential plane G20 described in FIG. 3A. On the tangential plane G20, positions are further apart by the first and second lengths (in this example, both are the thickness of the medium P10) described in the first exemplary embodiment from the processing unit (reader 3) than the tangential plane G10. Both of the first and second positions shown in FIGS. 7A to 7C are further toward the processing unit side than such positions on the tangential plane G20.

Additionally, if the surface speeds of the respective rotating members of the first transporting member 30 a and the second transporting member 40 a are defined as V1a and V2a, similarly to the first exemplary embodiment, the rotating members rotate so as to satisfy V2a>V1a. That is, the second transporting member 40 a rotates so that a speed (that is, surface speed) at which the surface of a rotating member of the second transporting member moves is faster than a surface speed in the first transporting member 30 a.

[2-2] Effects According to Second Exemplary Embodiment

In the present exemplary embodiment, the medium is transported so that the first surface passes through the tangential plane G10 as the first transporting member 30 a and the second transporting member 40 a contact the second surface at the first and second positions, respectively. If a fixed contact member like the first contact member 11 contacts the medium, a frictional force is generated in a direction in which the motion of the medium in the transporting direction A1 is hindered. On the other hand, since the first and second transporting members contact the second surface at the first and second positions, respectively, while the respective rotating members thereof rotate and transport the medium, the frictional force generated in the direction in which the motion of the medium in the transporting direction A1 becomes small compared to the fixed contact member. Accordingly, according to the present exemplary embodiment, a driving force required for the transport of the medium becomes small compared to a case where a contact member that does not rotate contacts the second surface.

Additionally, even in the present exemplary embodiment, the first transporting member 30 a and the second transporting member 40 a transport a medium, respectively, so that the respective surface speeds thereof become V1a<V2a. As a result, similarly to the first exemplary embodiment, a medium does not sag easily in the transporting direction compared to a case where the respective rotating members do not rotate at the speeds V1a and V2a.

[3] Modification Examples

The above-described exemplary embodiments are merely examples of implementation of the invention, and may be modified as follows. Additionally, the above-described respective exemplary embodiments and the respective modification examples shown below may be combined and implemented, if necessary.

[3-1] First and Second Positions

In the first exemplary embodiment, the first position is further apart by the first length from the processing unit than the tangential plane G10, and the second position is further apart by the second length from the processing unit than the tangential plane G10 (the processing unit is the reader 3, and both of the first and second lengths are the thickness L2 of the medium P10). However, the first and second positions are not limited to this.

FIG. 8 is a view showing an example of a hardware configuration of a transporting device of the present modification example. A transporting path 2 b on which the third contact member 21 and the fourth contact member 22 are provided so that the tangential plane G20 is located above the tangential plane G10 is shown in this example. Even in this case, a medium transported along the transporting path 2 b receives an upward force from the respective contact portions of the third contact member 21 and the fourth contact member 22 and is brought into a state where the first surface is pressed against the first contact portion C11 and the second contact portion C12. As a result, the first surface of the medium continues contacting both of the first contact portion C11 and the second contact portion C12, and a state where the first surface and the tangential plane G10 overlap each other is maintained in the section H1.

Additionally, in the second exemplary embodiment, the first and second positions are located further toward the processing unit side than the positions further apart by the first and second lengths (both are the thickness L2 of the medium P10) from the processing unit than the tangential plane G10. However, the first and second positions are not limited to this.

FIG. 9 is a view showing an example of contact members of the present modification example. In this example, a transporting path 2 c on which the third contact member 21 and the fourth contact member 22 are not provided, and the tangential planes G10 and G30 are shown. The tangential plane G30 is a plane including the nip regions N1 and N2, and the distance thereof from the tangential plane G10 is L3 similarly to the example of FIG. 3A. In this case, if the medium P10 (whose thickness is L2 that is twice greater than L3) shown in FIG. 3A is transported along the transporting path 2 c, the medium P10 is brought into a straight extending state in the transporting direction A1 as shown in FIG. 4A. As a result, the first contact portion C11 and the second contact portion C12 continue contacting the first surface of the medium P10, and a state where the first surface and the tangential plane G10 overlap each other is maintained in the section H1. As described above, the contacting unit has only to contact the second surface of a medium, at the positions further apart by the first and second lengths from the processing unit than the tangential plane G10 or at the first and second positions that are positions located further toward the processing unit side than these positions.

[3-2] Changing of Distance between First and Second Positions and Tangential Plane

In the above respective exemplary embodiments, the first and second positions may be moved in the vertical direction A3.

FIGS. 10A and 10B are views showing an example of a hardware configuration of a transporting device of the present modification example. In this example, a transporting device 1 d including a contacting unit 20 d is shown. The contacting unit 20 d includes the third contact member 21 and the fourth contact member 22. The contacting unit 20 d is connected to a changing unit 50. The changing unit 50 is an example of a changing unit that moves the contacting unit 20 d in the vertical direction A3 to change distances (hereinafter referred to as a “first tangential plane distance”) between the first position and the tangential plane G10, and the distance (hereinafter referred to as a “second tangential plane distance”) between the second position and the tangential plane G10. In the following, a case where both of the first and second tangential plane distances are meant is simply referred to as “tangential plane distances”.

The changing unit 50 includes a controller 51 and a drive 52. The controller 51 includes Central Processing Unit (CPU), Read Only Memory (ROM) and Random Access Memory (RAM), and the CPU executes a program stored in the ROM using the RAM as a work area to thereby control the operation of the drive 52. The drive 52 moves the contacting unit 20 d to a predetermined position in the vertical direction A3 as a stepping motor or the like rotates. The changing unit 50 changes the tangential plane distances as follows as the drive 52 controlled by the controller 51 is driven.

A state where the respective first and second tangential plane distances are L2 is shown in FIG. 10A. In this state, in the case of the medium P10 (medium having a thickness of L2) shown in FIGS. 4A to 4C, as shown in FIG. 4A, the medium is brought into a straight extending state in the transporting direction A1 and is transported. A state where both of the first and second tangential plane distances are L0 is shown in FIG. 10B. L0 represents that the length is 0 in this example. In this state, the medium P10 receives forces upward and downward by the respective contact portions, and is transported in a bent state.

The changing unit 50 changes the tangential plane distances according to, for example, the thickness of a medium transported. When the thickness of the medium transported is smaller than L2, the first surface does not contact the first contact portion C11 and the second contact portion C12 in a state shown in FIG. 10A. When the medium having such a thickness is transported, the contacting unit 20 d is moved so as to be brought into a state shown in FIG. 10B. Additionally, when the medium transported is cardboard, the cardboard is not easily bent. Therefore, the medium may be caught in one of the contact members in the state shown in FIG. 10B, and the transport itself may not be performed. The changing unit 50 changes the respective first and second tangential plane distances to L0 when, for example, the thickness of a medium is smaller than L2, and changes the respective first and second tangential plane distances to L2 when the thickness of a medium is equal to or more than L2. By changing the first and second tangential plane distances according to the thickness of a medium in this way, even if the thicknesses of respective media are different, the media are easily transported compared to a case where the tangential plane distances are changed regardless of the thickness of the medium.

In addition, the changing unit 50 may include, for example, a manipulating section receiving user's manipulation, to thereby change the tangential plane distances according to the user's manipulation. Additionally, the changing unit 50 may change the tangential plane distances according to the speed (transporting speed) of a medium transported along a transporting path 2 d. In this case, the changing unit 50 sets the respective first and second tangential plane distances to L2 if, for example, the transporting speed is equal to or higher than a threshold and sets the respective first and second tangential plane distances to L0 if the transporting speed is lower than the threshold. When both of the first and second tangential plane distances are L2, the resistance (this is referred to as “transport resistance”) that a medium transported receives from the contact members becomes small compared to the case of L0.

On the other hand, when both of the first and second tangential plane distances are L0, the transport resistance becomes large compared to the case of L2. However, along with this, the forces of pressing the medium against the first contact portion C11 and the second contact portion C12 also become large, and consequently, the first surface more easily passes through the tangential plane G10. Thus, by changing the tangential plane distances as mentioned above, the transport resistance is made small when the transporting speed is large so that the medium is smoothly transported, and the forces of pressing a medium against the first contact portion C11 and the second contact portion C12 are strengthened when the transporting speed is small so that the first surface more easily passes through the tangential plane G10. As such, according to the present modification example, the resistance received when a medium is transported in the transporting direction is adjusted, and the smoothness of transport of the medium or the passage of the first surface through the tangential plane G10 is adjusted using the resistance.

Additionally, the changing unit 50 may change the tangential plane distances by a method different from that shown in FIGS. 10A and 10B.

FIG. 11 is a view showing another example of a hardware configuration of a transporting device of the present modification example. A transporting device 1 e including a transporting path 2 e, a contacting unit 20 e, and a changing unit 50 e is shown in this example. The changing unit 50 e includes a controller 51 and a rotating section 53. The rotating section 53 is provided at the end portion of the contacting unit 20 e on the upstream side in the transporting direction A1, has a stepping motor or the like that is not shown, and rotates the contacting unit 20 e around an axis along the width direction A4 shown in FIG. 2 to change the first and second tangential plane distances, respectively. In this case, since the second position distant from the axis moves greatly in the vertical direction A3 compared to the first position near the axis, the second tangential plane distance changes more greatly than the first tangential plane distance.

[3-3] Glass Cover

In the above respective exemplary embodiments, the processing unit is provided in a space that forms a string along with the transporting path. However, for example, a glass cover may be provided at a boundary between the processing unit and the transporting path. As a result, the leading edge of a medium does not collide with the processing unit. Additionally, in the transporting device, both the surfaces of the first contact member 11 and the second contact member 12 on the upstream side in the transporting direction A1 guide the leading edge of a medium downward. Therefore, compared to a case where the contact members are not provided, the medium does not easily collide with the glass cover, and also, an event in which the glass cover becomes dirty due to substance (ink, a correction fluid, or the like) adhering to the first surface of the medium does not occur easily.

[3-4] Processing Performed by Processing Unit

In the above respective exemplary embodiments, the transporting device includes the reader 3 as the processing unit. However, the processing unit is not limited to this. For example, the transporting device may function as an image forming apparatus that includes a jetting device jetting ink onto a medium as the processing unit and that forms an image by an ink jet method. In short, the processing unit has only to perform certain processing on one surface (first surface) of a medium. Particularly, it is desirable to apply the invention to a case where a change in the position of the first surface with respect to the processing unit is apt to influence the results of processing.

[3-5] Shape of Contact Portion

The respective contact portions may have a form that is more sharpened than that shown in FIGS. 3A and 3B or the like. Even in such a case, since it is necessary to have a curved surface formed if the tips (that is, contact portions) of the respective contact members are enlarged, the respective contact portions will have tangential planes. However, it is desirable that the respective contact portions be roundish to such a degree that the contact portions do not damage a medium that collides with them.

Additionally, although the respective contact portions have a straight extending form without being cut along the width direction A4 in FIGS. 3A and 3B or the like, the invention is not limited to this. The form of the respective contact portions will be described using the form of contact regions where the first surface of a medium contacts the first and second contact portions.

FIGS. 12A to 12D are views showing examples of the contact regions of the present modification example. Contact regions D11f and D12f that extend straight without being cut along a direction A9 that forms an angle in the width direction A4 are shown in FIG. 12A. In this case, the first contact portion and the second contact portion have a straight extending form without being cut along the direction A9. Contact regions D11g and D12g that intermittently extend along the width direction A4 are shown in FIG. 12B. In this case, the first contact portion and the second contact portion have a form that extend straight along the width direction A4 and is depressed in some places on the way.

Contact regions D11h and D12h that extend without being cut along the width direction A4 and have a longer length (in this example, the length is L6) in the transporting direction A1 than the contact regions D11 and D12 shown in FIG. 2 are shown in FIG. 12C. In this case, the first and second contact portions have a planar form whose length in the transporting direction A1 is L6. In this case, a common tangential plane of the first and second contact portions includes a plane whose length in the transporting direction A1 is L6.

A case where a processed portion F1i processed by the processing unit does not include the end portions of a medium in the width direction A4 is shown in FIG. 12D. Contact regions D11i and D12i that extend along the width direction A4 are shown in this example. Although the contact regions D11i and D12i extend further toward the end portions of a medium in the width direction A4 than the processed portion F1i, the contact regions do not extend up to the end portions. In this case, although the first and second contact portions extend further toward the end portions of a medium in the width direction A4 than the processed portion F1i, the first and second contact portions have a form that does not extend up to the end portions. As such, it is desirable that the first and second contact portions extend longer than the processed portion in the width direction A4.

[3-6] Shape of Contact Member

In the above respective exemplary embodiments, the respective contact members have a common tangential plane along the transporting direction. However, the invention is not limited to this.

FIGS. 13A and 13B are views showing an example of contact members of the present modification example. The first contact member 11 shown in FIG. 3A is shown in this example, and a second contact portion C12j of a second contact member 12 j located above the first contact portion C11 of that first contact member 11 is shown. For this reason, a common tangential plane G10j of both of contact portions inclines with respect to the transporting direction A1. Additionally, a third contact portion C21j of a third contact member 21 i is located below a fourth contact portion C22j of a fourth contact member 22 j, and a common tangential plane G20j of both of the contact portions also inclines with respect to the transporting direction A1. The distance between the tangential planes G10j and G20j is L2 similarly to the example of FIG. 3A.

A state where the medium P10 having the thickness L2 is transported along the transporting path is shown in FIG. 13B. In this example, the first transporting member is provided so that a nip region is located above the third contact portion C21j, and the second transporting member is provided so that a nip region is located below the fourth contact portion C22j. For this reason, the medium P10 is pressed upward at the position (a first position in the present modification example) of the nip region N1 of the first transporting unit and the position (a second position in the present modification example) of the fourth contact portion C22j, and is transported while the first surface Q11 continues contacting the first contact portion C11 and the second contact portion C12j. That is, even in the present modification example, when a medium having a thickness equal to or more than the first and second lengths (L2 in this example) is transported, the first surface Q11 passes through the tangential plane G10j in a section of the first contact portion C11 to the second contact portion C12j. As a result, similarly to the above respective exemplary embodiments, the position of the first surface with respect to the processing unit does not easily change compared to a case where the configuration shown in FIGS. 13A and 13B is not included, even if the thicknesses of media are different.

[3-7] Orientation of Transporting Direction

In the above respective exemplary embodiments, the transporting direction runs along the horizontal direction A2. However, the invention is not limited to this. For example, the transporting direction may run along the vertical direction A3 or may run along a direction (inclining direction) intersecting these directions. That is, the transporting path may transport a medium in any direction. Additionally, the transporting path may have a form that draws a circular-arc (curve). Even in this case, if the first and second contact members and the transporting unit are included as shown in the above respective examples, the position of the first surface with respect to the processing unit does not easily change compared to a case where the first and second contact members and the transporting unit are not included, even if the thicknesses of media are different.

[3-8] Category of Invention

The invention is grasped as an inspection device or an image reading apparatus that outputs the results of reading by the reader 3, in addition to the above-described transporting device. Additionally, if a jetting device that jets ink jet on a medium is included as the processing unit, the invention is also grasped as an image forming apparatus that jets ink onto a medium transported and forms an image. In short, the invention performs processing on the first surface of a medium transported, and may be applied to any types of devices as long as it is desirable that the position of the first surface with respect to the processing unit be stable.

The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents. 

What is claimed is:
 1. A transporting device comprising: a first contact member having a first contact portion that contacts a medium transported; a second contact member having a second contact portion that contacts the medium transported, on the downstream side of the first contact portion in a transporting direction, the first contact portion and the second contact portion each having a tangential plane, and the tangential planes coinciding with each other; a transporting unit that transports the medium so that a first surface of the medium coincides with the tangential plane in a section of the first contact portion to the second contact portion; and a processing unit that is arranged between the first contact portion and second contact portion, and performs processing on the first surface of the medium that is passing through a processing region.
 2. The transporting device according to claim 1, wherein the transporting device has a contacting unit that contacts a second surface of the medium opposite to the first surface, and the contacting unit contacts the second surface at a first position and a second position.
 3. The transporting device according to claim 2, wherein the contacting unit includes a third contact member having a third contact portion that contacts the medium transported, at the first position, and a fourth contact member having a fourth contact portion that contacts the medium at the second position.
 4. The transporting device according to claim 1, wherein the transporting unit includes: a first transporting member which has a first rotating member that is provided on the upstream side of the first contact member in the transporting direction and the first contact member rotates to transport the medium contacting a surface of the first rotating member; and a second transporting member which has a second rotating member that is provided on the downstream side of the second contact member in the transporting direction and the second contact member rotates to transport the medium contacting a surface of the second rotating member, and wherein a speed at which the surface of the second rotating member moves is faster than a speed at which the surface of the first rotating member moves.
 5. The transporting device according to claim 2, wherein the transporting unit includes: a first transporting member which has a first rotating member that is provided on the upstream side of the first contact member in the transporting direction and the first contact member rotates to transport the medium contacting a surface of the first rotating member; and a second transporting member which has a second rotating member that is provided on the downstream side of the second contact member in the transporting direction and the second contact member rotates to transport the medium contacting a surface of the second rotating member, and wherein a speed at which the surface of the second rotating member moves is faster than a speed at which the surface of the first rotating member moves.
 6. The transporting device according to claim 3, wherein the transporting unit includes: a first transporting member which has a first rotating member that is provided on the upstream side of the first contact member in the transporting direction and the first contact member rotates to transport the medium contacting a surface of the first rotating member; and a second transporting member which has a second rotating member that is provided on the downstream side of the second contact member in the transporting direction and the second contact member rotates to transport the medium contacting a surface of the second rotating member, and wherein a speed at which the surface of the second rotating member moves is faster than a speed at which the surface of the first rotating member moves.
 7. The transporting device according to claim 2, wherein the contacting unit includes: a first transporting member which has a first rotating member that is provided on the upstream side of the first contact member in the transporting direction and the first contact member rotates to transport the medium contacting a surface of the first rotating member; and a second transporting member which has a second rotating member that is provided on the downstream side of the second contact member in the transporting direction and the second contact member rotates to transport the medium contacting a surface of the second rotating member, and wherein the first transporting member contacts the second surface at the first position, and the second transporting member contacts the second surface at the second position.
 8. The transporting device according to claim 7, wherein a speed at which the surface of the second rotating member moves is faster than a speed at which the surface of the first rotating member moves.
 9. The transporting device according to claim 2, further comprising: a changing unit that changes the distances between the first positions and the tangential plane and changes the distances between the second positions and the tangential plane.
 10. The transporting device according to claim 3, further comprising: a changing unit that changes the distances between the first positions and the tangential plane and changes the distances between the second positions and the tangential plane.
 11. The transporting device according to claim 4, further comprising: a changing unit that changes the distances between the first positions and the tangential plane and changes the distances between the second positions and the tangential plane.
 12. The transporting device according to claim 7, further comprising: a changing unit that changes the distances between the first positions and the tangential plane and changes the distances between the second positions and the tangential plane.
 13. The transporting device according to claim 9, a changing unit that changes the distances between the first positions and the tangential plane and changes the distances between the second positions and the tangential plane.
 14. The transporting device according to claim 10, a changing unit that changes the distances between the first positions and the tangential plane and changes the distances between the second positions and the tangential plane.
 15. The transporting device according to claim 11, a changing unit that changes the distances between the first positions and the tangential plane and changes the distances between the second positions and the tangential plane.
 16. An image reading apparatus comprising: the transporting device according to claim 1, wherein the processing unit is a reading unit.
 17. An image forming apparatus comprising: the transporting device according to claim 1, wherein the processing unit is an ink jet recording unit. 